Published January 1986. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Geologic mapping of the Longview-Kelso area and the measurement and description of a composite 650-meter thick stratigraphic section of the Cowlitz Formation (Tc) in Coal Creek using bio-, magneto-, litho-, and sequence stratigraphy reveals a complex interplay of Cowlitz micaceous, lithic arkosic shelf to tidal/estuarine to delta
plain facies associations,...
The Tumalo quadrangle lies approximately 30 kilometers behind the Cascade volcanic arc and marks the southernmost extent of continuously exposed Deschutes Formation rocks. Deschutes Formation rocks in the
Tumalo quadrangle include late Miocene volcaniclastic sedimentary rocks, ignimbrites and lapillistones, and late Miocene to early
Pliocene basalts and basaltic andesites. Volcaniclastic...